clean up navigation a lot

Demos/UiDemo.cs

@@ -150,7 +150,9 @@ namespace Demos {
                 OnPressed = element => tooltip.IsHidden = !tooltip.IsHidden
             });
 
-            var slider = new Slider(Anchor.AutoLeft, new Vector2(1, 10), 5, 1);
+            var slider = new Slider(Anchor.AutoLeft, new Vector2(1, 10), 5, 1) {
+                StepPerScroll = 0.01F
+            };
             root.AddChild(new Paragraph(Anchor.AutoLeft, 1, paragraph => "Slider is at " + (slider.CurrentValue * 100).Floor() + "%") {PositionOffset = new Vector2(0, 1)});
             root.AddChild(slider);
 

MLEM.Ui/Elements/Element.cs

@@ -7,6 +7,7 @@ using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 using MLEM.Extensions;
 using MLEM.Input;
+using MLEM.Misc;
 using MLEM.Textures;
 using MLEM.Ui.Style;
 
@@ -449,6 +450,14 @@ namespace MLEM.Ui.Elements {
             return this.CanBeMoused && this.Area.Contains(position) ? this : null;
         }
 
+        public virtual Element GetTabNextElement(bool backward, Element usualNext) {
+            return usualNext;
+        }
+
+        public virtual Element GetGamepadNextElement(Direction2 dir, Element usualNext) {
+            return usualNext;
+        }
+
         public void AndChildren(Action<Element> action) {
             action(this);
             foreach (var child in this.Children)

MLEM.Ui/Elements/ElementHelper.cs

@@ -16,11 +16,12 @@ namespace MLEM.Ui.Elements {
         public static Panel ShowInfoBox(UiSystem system, Anchor anchor, float width, string text, float buttonHeight = 10, string okText = "Okay") {
             var box = new Panel(anchor, new Vector2(width, 1), Vector2.Zero, true);
             box.AddChild(new Paragraph(Anchor.AutoLeft, 1, text));
-            box.AddChild(new Button(Anchor.AutoCenter, new Vector2(0.5F, buttonHeight), okText) {
+            var button = box.AddChild(new Button(Anchor.AutoCenter, new Vector2(0.5F, buttonHeight), okText) {
                 OnPressed = element => system.Remove("InfoBox"),
                 PositionOffset = new Vector2(0, 1)
             });
-            system.Add("InfoBox", box);
+            var root = system.Add("InfoBox", box);
+            root.SelectElement(button);
             return box;
         }
 

MLEM.Ui/Elements/Panel.cs

@@ -38,7 +38,7 @@ namespace MLEM.Ui.Elements {
 
                 // handle automatic element selection, the scroller needs to scroll to the right location
                 this.OnSelectedElementChanged += (element, otherElement) => {
-                    if (this.Controls.SelectedLastElementWithMouse)
+                    if (!this.Controls.IsAutoNavMode)
                         return;
                     if (otherElement == null || !otherElement.GetParentTree().Contains(this))
                         return;

MLEM.Ui/Elements/Slider.cs

@@ -1,10 +1,31 @@
 using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+using MLEM.Misc;
 
 namespace MLEM.Ui.Elements {
     public class Slider : ScrollBar {
 
         public Slider(Anchor anchor, Vector2 size, int scrollerSize, float maxValue) :
             base(anchor, size, scrollerSize, maxValue, true) {
+            this.CanBeSelected = true;
+        }
+
+        public override void Update(GameTime time) {
+            base.Update(time);
+
+            if (this.IsSelected) {
+                if (this.Input.IsGamepadButtonDown(Buttons.DPadLeft) || this.Input.IsGamepadButtonDown(Buttons.LeftThumbstickLeft)) {
+                    this.CurrentValue -= this.StepPerScroll;
+                } else if (this.Input.IsGamepadButtonDown(Buttons.DPadRight) || this.Input.IsGamepadButtonDown(Buttons.LeftThumbstickRight)) {
+                    this.CurrentValue += this.StepPerScroll;
+                }
+            }
+        }
+
+        public override Element GetGamepadNextElement(Direction2 dir, Element usualNext) {
+            if (dir == Direction2.Left || dir == Direction2.Right)
+                return null;
+            return base.GetGamepadNextElement(dir, usualNext);
         }
 
     }

MLEM.Ui/UiControls.cs

@@ -16,13 +16,14 @@ namespace MLEM.Ui {
         private readonly UiSystem system;
 
         public Element MousedElement { get; private set; }
-        public Element SelectedElement { get; private set; }
+        public Element SelectedElement => this.GetActiveRoot()?.SelectedElement;
-        public bool SelectedLastElementWithMouse { get; private set; }
 
         public Buttons[] GamepadButtons = {Buttons.A};
         public Buttons[] SecondaryGamepadButtons = {Buttons.X};
         public int GamepadIndex = -1;
 
+        public bool IsAutoNavMode { get; private set; }
+
         public UiControls(UiSystem system, InputHandler inputHandler = null) {
             this.system = system;
             this.Input = inputHandler ?? new InputHandler();
@@ -48,17 +49,20 @@ namespace MLEM.Ui {
             }
 
             if (this.Input.IsMouseButtonPressed(MouseButton.Left)) {
+                this.IsAutoNavMode = false;
                 var selectedNow = mousedNow != null && mousedNow.CanBeSelected ? mousedNow : null;
-                this.SelectElement(selectedNow, true);
+                this.GetActiveRoot().SelectElement(selectedNow);
                 if (mousedNow != null)
                     mousedNow.OnPressed?.Invoke(mousedNow);
             } else if (this.Input.IsMouseButtonPressed(MouseButton.Right)) {
+                this.IsAutoNavMode = false;
                 if (mousedNow != null)
                     mousedNow.OnSecondaryPressed?.Invoke(mousedNow);
             }
 
             // KEYBOARD INPUT
             else if (this.Input.IsKeyPressed(Keys.Enter) || this.Input.IsKeyPressed(Keys.Space)) {
+                this.IsAutoNavMode = true;
                 if (this.SelectedElement?.Root != null) {
                     if (this.Input.IsModifierKeyDown(ModifierKey.Shift)) {
                         // secondary action on element using space or enter
@@ -69,76 +73,50 @@ namespace MLEM.Ui {
                     }
                 }
             } else if (this.Input.IsKeyPressed(Keys.Tab)) {
+                this.IsAutoNavMode = true;
                 // tab or shift-tab to next or previous element
-                this.SelectElement(this.GetTabNextElement(this.Input.IsModifierKeyDown(ModifierKey.Shift)), false);
+                var backward = this.Input.IsModifierKeyDown(ModifierKey.Shift);
+                var next = this.GetTabNextElement(backward);
+                if (this.SelectedElement?.Root != null)
+                    next = this.SelectedElement.GetTabNextElement(backward, next);
+                this.GetActiveRoot().SelectElement(next);
             }
 
             // TOUCH INPUT
             else if (this.Input.GetGesture(GestureType.Tap, out var tap)) {
+                this.IsAutoNavMode = false;
                 var tapped = this.GetElementUnderPos(tap.Position.ToPoint());
-                this.SelectElement(tapped, true);
+                this.GetActiveRoot().SelectElement(tapped);
                 if (tapped != null)
                     tapped.OnPressed?.Invoke(tapped);
             } else if (this.Input.GetGesture(GestureType.Hold, out var hold)) {
+                this.IsAutoNavMode = false;
                 var held = this.GetElementUnderPos(hold.Position.ToPoint());
-                this.SelectElement(held, true);
+                this.GetActiveRoot().SelectElement(held);
                 if (held != null)
                     held.OnSecondaryPressed?.Invoke(held);
             }
 
             // GAMEPAD INPUT
             else if (this.GamepadButtons.Any(b => this.Input.IsGamepadButtonPressed(b, this.GamepadIndex))) {
+                this.IsAutoNavMode = true;
                 if (this.SelectedElement?.Root != null)
                     this.SelectedElement.OnPressed?.Invoke(this.SelectedElement);
             } else if (this.SecondaryGamepadButtons.Any(b => this.Input.IsGamepadButtonPressed(b, this.GamepadIndex))) {
+                this.IsAutoNavMode = true;
                 if (this.SelectedElement?.Root != null)
                     this.SelectedElement.OnSecondaryPressed?.Invoke(this.SelectedElement);
             } else if (this.Input.IsGamepadButtonPressed(Buttons.DPadDown) || this.Input.IsGamepadButtonPressed(Buttons.LeftThumbstickDown)) {
-                var next = this.GetGamepadNextElement(searchArea => {
+                this.HandleGamepadNextElement(Direction2.Down);
-                    searchArea.Height += this.system.Viewport.Height;
-                    return searchArea;
-                });
-                if (next != null)
-                    this.SelectElement(next, false);
             } else if (this.Input.IsGamepadButtonPressed(Buttons.DPadLeft) || this.Input.IsGamepadButtonPressed(Buttons.LeftThumbstickLeft)) {
-                var next = this.GetGamepadNextElement(searchArea => {
+                this.HandleGamepadNextElement(Direction2.Left);
-                    searchArea.X -= this.system.Viewport.Width;
-                    searchArea.Width += this.system.Viewport.Width;
-                    return searchArea;
-                });
-                if (next != null)
-                    this.SelectElement(next, false);
             } else if (this.Input.IsGamepadButtonPressed(Buttons.DPadRight) || this.Input.IsGamepadButtonPressed(Buttons.LeftThumbstickRight)) {
-                var next = this.GetGamepadNextElement(searchArea => {
+                this.HandleGamepadNextElement(Direction2.Right);
-                    searchArea.Width += this.system.Viewport.Width;
-                    return searchArea;
-                });
-                if (next != null)
-                    this.SelectElement(next, false);
             } else if (this.Input.IsGamepadButtonPressed(Buttons.DPadUp) || this.Input.IsGamepadButtonPressed(Buttons.LeftThumbstickUp)) {
-                var next = this.GetGamepadNextElement(searchArea => {
+                this.HandleGamepadNextElement(Direction2.Up);
-                    searchArea.Y -= this.system.Viewport.Height;
-                    searchArea.Height += this.system.Viewport.Height;
-                    return searchArea;
-                });
-                if (next != null)
-                    this.SelectElement(next, false);
             }
         }
 
-        public void SelectElement(Element element, bool mouse) {
-            if (this.SelectedElement == element)
-                return;
-
-            if (this.SelectedElement != null)
-                this.SelectedElement.OnDeselected?.Invoke(this.SelectedElement);
-            if (element != null)
-                element.OnSelected?.Invoke(element);
-            this.SelectedElement = element;
-            this.SelectedLastElementWithMouse = mouse;
-            this.system.ApplyToAll(e => e.OnSelectedElementChanged?.Invoke(e, element));
-        }
-
         public Element GetElementUnderPos(Point position, bool transform = true) {
             foreach (var root in this.system.GetRootElements()) {
                 var pos = transform ? position.Transform(root.InvTransform) : position;
@@ -150,7 +128,7 @@ namespace MLEM.Ui {
         }
 
         private Element GetTabNextElement(bool backward) {
-            var currRoot = this.system.GetRootElements().FirstOrDefault(root => root.CanSelectContent);
+            var currRoot = this.GetActiveRoot();
             if (currRoot == null)
                 return null;
             var children = currRoot.Element.GetChildren(regardChildrensChildren: true).Append(currRoot.Element);
@@ -178,15 +156,44 @@ namespace MLEM.Ui {
             }
         }
 
-        private Element GetGamepadNextElement(Func<Rectangle, Rectangle> searchAreaFunc) {
+        private void HandleGamepadNextElement(Direction2 dir) {
-            var currRoot = this.system.GetRootElements().FirstOrDefault(root => root.CanSelectContent);
+            this.IsAutoNavMode = true;
+            Rectangle searchArea = default;
+            if (this.SelectedElement?.Root != null) {
+                searchArea = this.SelectedElement.Area;
+                var (_, _, width, height) = this.system.Viewport;
+                switch (dir) {
+                    case Direction2.Down:
+                        searchArea.Height += height;
+                        break;
+                    case Direction2.Left:
+                        searchArea.X -= width;
+                        searchArea.Width += width;
+                        break;
+                    case Direction2.Right:
+                        searchArea.Width += width;
+                        break;
+                    case Direction2.Up:
+                        searchArea.Y -= height;
+                        searchArea.Height += height;
+                        break;
+                }
+            }
+            var next = this.GetGamepadNextElement(searchArea);
+            if (this.SelectedElement != null)
+                next = this.SelectedElement.GetGamepadNextElement(dir, next);
+            if (next != null)
+                this.GetActiveRoot().SelectElement(next);
+        }
+
+        private Element GetGamepadNextElement(Rectangle searchArea) {
+            var currRoot = this.GetActiveRoot();
             if (currRoot == null)
                 return null;
             var children = currRoot.Element.GetChildren(regardChildrensChildren: true).Append(currRoot.Element);
             if (this.SelectedElement?.Root != currRoot) {
                 return children.FirstOrDefault(c => c.CanBeSelected);
             } else {
-                var searchArea = searchAreaFunc(this.SelectedElement.Area);
                 Element closest = null;
                 float closestDist = 0;
                 foreach (var child in children) {
@@ -202,5 +209,9 @@ namespace MLEM.Ui {
             }
         }
 
+        public RootElement GetActiveRoot() {
+            return this.system.GetRootElements().FirstOrDefault(root => root.CanSelectContent);
+        }
+
     }
 }

MLEM.Ui/UiSystem.cs

@@ -75,7 +75,7 @@ namespace MLEM.Ui {
             });
 
             this.OnSelectedElementDrawn = (element, time, batch, alpha) => {
-                if (!this.Controls.SelectedLastElementWithMouse && element.SelectionIndicator != null) {
+                if (this.Controls.IsAutoNavMode && element.SelectionIndicator != null) {
                     batch.Draw(element.SelectionIndicator, element.DisplayArea, Color.White * alpha, element.Scale / 2);
                 }
             };
@@ -176,12 +176,26 @@ namespace MLEM.Ui {
         public Matrix Transform = Matrix.Identity;
         public Matrix InvTransform => Matrix.Invert(this.Transform);
 
+        public Element SelectedElement { get; private set; }
+
         public RootElement(string name, Element element, UiSystem system) {
             this.Name = name;
             this.Element = element;
             this.System = system;
         }
 
+        public void SelectElement(Element element) {
+            if (this.SelectedElement == element)
+                return;
+
+            if (this.SelectedElement != null)
+                this.SelectedElement.OnDeselected?.Invoke(this.SelectedElement);
+            if (element != null)
+                element.OnSelected?.Invoke(element);
+            this.SelectedElement = element;
+            this.System.ApplyToAll(e => e.OnSelectedElementChanged?.Invoke(e, element));
+        }
+
         public void MoveToFront() {
             this.System.Remove(this.Name);
             this.System.Add(this);